Sustainable Rating System

New Zealand is on course to implement a nation-wide sustainability rating system for commercial office buildings and subsequently a framework to cover other building types and uses.

The rating system will likely be developed by the New Zealand Green Building Council with the backing of the Ministry for the Environment (MfE). The MfE provided significant funding for the council to analyse and identify the most suitable office building assessment scheme.

Under a schedule set by the Green Building Council it is planned to agree a suggested office and commercial buildings rating scheme by the end of June.  It is to be a system aligned with internationally accepted assessment procedures.

In support of this move, the MfE commissioned a “Value Case” study by David Fulbrook, of E Cubed Building Workshop, and Graeme Finlay, a Principal of architectural firm, Warren and Mahoney.

Their study indicated that a whole-of-life cost view of sustainable building indicates a marginal cost increase is likely to be repaid between five or six times by operating cost savings alone. An initial capital cost comparison showed costs of a sustainable building varying between 15 percent less and 11.5 percent more than a good quality conventional building. Sustainable features initially cost on average about two to six percent more.

The authors’ said a residual land value analysis found that a sustainable office building may have a land value of 40 percent more than that of a conventional structure.

The position of tenants was covered in an estimate that a probable 20 year rental premium was likely to be repaid by a factor of approximately three from operating costs only.